Answers

Hello,

Although each home is unique in design, it's safe to say that virtually every home should have a properly vented ROOF. A properly insulated home, with a properly vented roof, should not have a condensation problem.

Ventalation is one of the most important parts of your roofing system.  Has proper intake air flow coming in from the eaves of your home, where your gutters are located, and exausting through the ridge of your home.  All roofing manufactors require this as part of there warranty information because it does not only affect the condisation in your attic space but will also weaken your shingles and lower there live span.  If your home already has proper insolation and proper ventatation another option would be to add a power fan unit on your roof near the ridge with a humidistat built it.  This will turn on automatically at whatever tempature you set and also when moisture builds but will turn on.  Moisture in the attic space is common in winter months due to cold tempatures outside and heat from your attic space meeting.  I would have a roofing company come out and inspect your soffits to make sure they are ventalated and also to ensure you have a ridge vent installed on your home to start.  

Ideally, you will have no sweating if you have proper insulation and ventialtion. Generally moisture forms by ice freezing on the bottom side of the roof sheathng or the nails sticking through tje shething and when it melts you have water( sweating.) Not good. This can lead to wet insulation, mold and deterioration of the sheathing and or framing members. Get itchecked by a professional. 

Proper ventilation is extremely important for a long lasting roof. If you roof is sweating and creating condenstaion it can deteriorate your entire roofing system from the decking and supports to the underlayment and shingles. Also, depending on your climate, inproper ventilation will contribute to ice dams. I'd recommend cutting in a roof long ridge vent as soon as possible.

Proper ventilation plays an important role in prolonging the life of your roof. During winter, attic ventilation is needed to prevent ice dams from forming, and during the hot summer months, ventilation helps to remove hot air which reduces mold growth and protects the shingles from excessive heat. Choosing the best attic ventilation is an important part of the process. Turbines or Ridge Vents are 2 of the choices. A turbine system is installed directly on the top of a roof and uses wind power to suck hot and humid air out of the attic. A turbine has a series of vanes that spin as wind passes through them. They are less costly dues to the fact that only a few shingles need to be removed and an appropriately sized hole is then drilled through the roof. Turbines do cause more air movement than ridge vents and this is due to their moving vanes. However if you do not live somewhere that has winds or are sheltered from them this system may not work as effectively when the weather gets very hot during the Summer season. A ridge vent runs across the top of the roof's peak. Unlike turbines, this venting style does not have any moving parts. A ridge vent is similar to a screen and allows heat to escape up and out of the attic. Ridge vent systems normally run the full length of the roof. For this system to be installed on an existing roof, the entire peak must be cut away, which can make the installation more expensive than installing a turbine. They cannot be installed on a flat roof or one with a pitch of less than 212 degrees. A ridge vent is a passive system and offers less air movement, and in moderate climates this style tends to be sufficient. In more extreme climates, one or more turbines will provide better circulation. For optimal performance, ridge vents require soffit venting to bring air up and out the top of the roof. Roof ridge vents help to release moisture from homes, which is especially useful during the winter when moisture has a greater impact. Ventilation With the help of wind, a ventilation system is created in the attic with a roof ridge vent. As wind passes over the roof ridge vent, it draws air out of the attic. The problem with traditional roofing is that once the outside air goes into the attic, it has no way to escape. Roof ridge-vent allows the outside air that enters to escape out the top of the roof, preventing damage--such as premature aging and cracking--to the attic and roof. With the help of wind, a ventilation system is created in the attic with a roof ridge vent. As wind passes over the roof ridge vent, it draws air out of the attic. Fresh air is then drawn into the underside of the vent, creating a circulation system of fresh air. Moisture can be released from many activities that are performed within homes, including running a washer, using a dishwasher or taking a shower. Moisture is one of the leading causes of damage to rafters, shingles, walls and insulation within homes. Roof ridge vents help to release moisture from homes, which is especially useful during the winter when moisture has a greater impact. Most homeowners prefer the look of roof ridge vents--which are sleek and blend in well with the other shingles--to other forms of ventilation systems, which often consist of large fans, turbines and vents. Other Systems Another benefit of roof ridge ventilation systems is that they are effective without being used in combination with other systems. Other types of ventilation systems, such as fans and powered ventilators, can even have an adverse effect when used with roof ridge vents because of airflow issues. It is very important that's your roof and roof system is installed correctly by a licensed roofing contractor. A roofing contractor can also help you determine the best type of attic ventilation for your home.

Roof ventilation is very important.  Ensure that the intake from the eaves is adequate and not blocked in the attic with insulation.  Ensure you have adequate exhausting on the ridges.  Proper ventilation can extend the life of your roof.  If you have any questions, you should consult with a roofing professional in your area.

Proper ventillation is one of the most important factors in your roof lasting it's full lifespan, looking great for decades, and not creating black mold issues in your attic or crawl space. Not only do most roofing manufaturers such as CertainTeed and GAF require it allow certified installers to offer lifetime manufacturer warranties with features such as being fully transferrable and non-prorated; International Residential Code also requires proper ventillation for your roof to meet 2018 code standards. You need proper intake from a source such as functional vents in the eves with vented soffits or from smart vents. You also need proper ventillation out from sources such as a working attic fan or a ridgevent. Also be careful - more isn't always better as it can affect the air flow direction in the attic space. For example - you do not want both a running attic fan AND a ridgevent or the fan will pull air IN (not out) from the ridgevent instead of the intake locations and air will not circulate properly and will not meet many manufacturer requirements.

Thanks for the valuable information.